NUCLEAR experts are baffled by higher than usual levels of radiation in the Czech Republic and neighbouring countries.

The International Atomic Energy Agency (IAEA) last night launched an investigation into the increased levels of iodine-131 which have been measured in the atmosphere over the Czech Republic and elsewhere on the continent.

The agency said the radiations levels don't seem to pose a health hazard and that the radioisotope will lose much of its radiation in about eight days.

However, sources within the nuclear agency said the release appeared to be continuing.

While the cause is not known, the IAEA says it is not the result of Japan's Fukushima Daiichi nuclear disaster.

Tests

In Prague, an official at the Czech State Office for Nuclear Safety said he was "100pc sure" that the radiation had not come from any Czech nuclear power plant -- or from any other source on Czech territory.

The official said tests are under way around the country to try to identify the source.

The Czechs are investing heavily on nuclear power and have plans to increase production -- a move that would give the country a place among Europe's most nuclear-dependent nations. They currently rely on six nuclear reactors for 33 percent of their total electricity. The government hopes to at least double that output.

That's in stark contrast to its neighbours: German Chancellor Angela Merkel's government has decided to phase out nuclear energy by 2022 and Switzerland has followed suit, while Austria abandoned nuclear energy after the 1986 Chernobyl nuclear disaster and strictly opposes the Czech nuclear programme.